This competing renewal of the Postgraduate Training Program in Epithelial Biology, AR07422, aims to extend 35 continuous years of NIH-supported postdoctoral training in skin research at Stanford. The program objective is to train postdoctoral fellows for future careers in research. The rationale for the multi- disciplinary design of the program within the Stanford Program in Epithelial Biology is based on the premise that future success in cutaneous biology research will be enhanced by training interactions within a broad scientific network. Developments during the prior funding cycle include: 1) Expansion of the Stanford Program in Epithelial Biology (PEB): AR07422 is the heart of the multi- disciplinary PEB, which has grown to 67 Stanford faculty united by themes common to skin and other epithelial tissues, including differentiation, morphogenesis, adhesion, stem cell biology, carcinogenesis, and therapeutics, which together comprise T32 training foci. The current proposal has also expanded to include training opportunities in translational and population sciences research, directed by world leaders in those fields. 2) Enrichment of the T32 training environment: Embedded among basic science faculty, the core Dermatology labs leading this T32 have been further enriched by 24 Ph.D. students pursuing thesis efforts, a 25% expansion in research space in 2016, new equipment, new high throughput genomics core facilities, and a new in-lab core biocomputational training resource. 3) Enhancement of multi-disciplinary resources available to trainees: In addition to the PEB, T32 mentors expanded their involvement and leadership in additional multi-disciplinary programs at Stanford, spanning Stanford Stem Cell Biology, Cancer Biology, and Genomics Programs. 4) Acceleration of the scientific productivity of the Stanford skin research training community: Productivity, measured by high impact papers (journal ISI impact factor >25) has accelerated, with 28 such publications from the core Dermatology mentors over the prior funding cycle. 5) Successful training of future PIs: 12 Research P.I.s graduated from the laboratories of the 4 Dermatology core mentors over the current funding cycle and are now Assistant Professors at institutions that include Stanford (3), Northwestern, UC-San Francisco (UCSF), UC-Irvine (UCI, 2), UC-San Diego (UCSD, 2), MSKCC and the University of Pennsylvania (2). The Stanford Postgraduate Training Program in Epithelial Biology, AR07422, aims to train postdoctoral fellows to become future leaders in the field of research relevant to skin disease.